The girls were taken from a school in the town of Chibok by members of the Islamist group Boko Haram.

The kidnapping of the 276 girls triggered the global social media campaign #BringBackOurGirls.

The campaign involved US first lady Michelle Obama and a host of celebrities. Despite their efforts, most of the girls are still missing. Thursday marks the second anniversary of their disappearance.

The footage of the girls is the first to be seen since May 2014, when about 100 of them were shown in a video.

But Nigeria’s Information Minister Lai Mohammed urged caution, saying the government had received a similar video last July that led to a “cul-de-sac”.

He queried why it had been released now, if filmed in December, but stressed the government was “ready to explore all avenues that will lead to the release of the girls”.

The footage was broadcast after being handed to the Nigerian government.

Apparently filmed on Christmas Day 2015, it shows the girls pleading with the Nigerian government to co-operate with militants on their release.

They said they were being treated well but wanted to be with their families.

One girl named only as Saa, who escaped soon after being abducted and now lives in the US, spotted three of her friends.

“The moment I saw them and recognized their faces, I started crying, with tears of joy rolling down from my eyes, thanking God for their lives,” she said in a statement issued through the Education Must Continue Initiative, a Washington-based charity that supports nine escapees.

“Seeing them gives me the courage to tell the world today that we should not lose hope.

“I want the world to raise their voice. Let’s not stop until the government hears us and does something about it.”